Singe was originally to be a black drake that served as a pet or advisor to Grom Hellscream in the cancelled Warcraft Adventures: Lord of the Clans. It's unknown if he was meant to be an enemy (perhaps manipulating Grom) and perhaps having connections to Deathwing who was also in the game. Because Warcraft Adventures was cancelled, the status as Grom's companion likely is not part of lore.